Twin bombs exploded in the upscale resort of Hua Hin late Thursday, killing one woman and wounding more than 20 others, including nine foreign tourists, and were followed by two more on Friday morning that killed another person.
A further two blasts struck Friday in the popular tourist town of Phuket, while two more bombs were reported in the southern provinces of Trang and Surat Thani, in each of which one person was killed.
Prime Minister Prayut Chan-O-Cha called for calm and said he did not know who was behind the attacks.
“The bombs are an attempt to create chaos and confusion,” he told reporters. “We should not make people panic more.”
“Why the bombs occurred as our country is heading towards stability, a better economy and tourism — and who did it — you have to find out for me,” he added.
The two bombs that went off in Hua Hin on Thursday evening were hidden in potted plants and went off within 30 minutes of each other in the bar district of the popular beach town.
While small bombings are common in the kingdom during periods of heightened political tension, there have been few such incidents in the past year and it is rare for tourists to be targeted.
Hua Hin is home to the summer palace of Thailand’s revered royal family and the blast came on the eve of Queen Sirikit’s 84th birthday and just ahead of the first anniversary of a Bangkok shrine bombing that killed 20.
Authorities were searching for leads on the attackers and a motive behind the latest blasts.
Hua Hin’s district chief, Sutthipong Klai-udom, told AFP that the bombs on Thursday evening were detonated by mobile phone.
According to staff at local hospitals, German, Italian, Dutch and Austrian nationals were among the wounded.
“It was very shocking. There was a loud noise and police were running everywhere, it was terrible,” said Michael Edwards, an Australian tourist staying in a guest house close to where the second bomb detonated.
“I was just surprised that it happened here… now I’m thinking if it’s worth staying,” he told AFP.